Circuit controlling apparatus



Dec. 24, 1935, A THQMAS 2,25,13

CIRCUIT CONTROLLING APPARATUS Filed July 10, 1929 4 Sheets-Sheet lINVENTOR DEQ. 24, 1935: A A, THOMAS 2,@25,135

CIRCUIT CONTROLLING APPARATUS Filed July 10, 1929 4 Sheets-Sheet 2 Dec.24, 1935., A. A. TH 5MAS 2,@25,136

C IRCUIT CONTROLLING APPARATUS Filed July 10, 1929 4 Sheets-Sheet 5 INVENTOR Mina.

D86. 24, 1935: A, A T s ZQZSJSQ CIRCUIT CONTROLLING APPARATUS Filed July10, 1929 4 Sheets-Sheet 4 Patented Dec. 24, 1935 UNITED STATES PATENTOFFICE CIRCUIT CONTROLLING APPARATUS Adolph A. Thomas, New York, N. Y.

Application July 10, 1929, Serial No. 377,108

24 Claims. (Cl. 175-320) This invention is for a novel device adapted tocontrol automatically the operation of electric appliances in apredetermined manner, irrespective of whether the current is direct oralternating. One object of my invention is to regulate the temperatureof electric heating utensils in the home, such as fiat irons, toasters,percolators, wafiie irons, and others. Another use of my new device isfor automatically cutting an electric ino strument out of circuit aftera certain lapse of time. For example, radio receivers, electric fans,heating pads, washing machines, violet ray lamps,

(in fact, any kind of electrically operated mechanism) when connected tomy control device, will 1., automatically cease to operate at apredetermined moment. A further feature of my invention includesadjustable means whereby an electric circuit either is periodicallyopened and closed automatically, as for controlling the temperature of39 a heating appliance, or remains open until manually closed.

In its practical embodiment, my circuit controller comprises a small boxwhich contains the operative parts. An electric cord attached to the2;,- box is plugged into a house-lighting socket. The

instrument to be controlled is connected to a pair of switch terminalsin the box, which may be put on a table, chair or in some otherconvenient place. A suitable finger piece (such as a rotary knob, but- 3ton, or lever) enables a person to regulate the working temperature of aheating appliance connected to the control box. This regulation oftemperature is eilected by a thermostatic switch adapted to open andclose the heating circuit at 3;, predetermined intervals, which may bevaried by simply turning the knob or other finger piece. If th controlbox is used with a device intended to be permanently put out ofoperation after a certain'length of time, the knob is turned to vary 40that interval as desired. This finger piece is also adjustable toeliminate the time control, so that the circuit remains closed withoutinterruption until opened by hand. Another movable finger piece on thebox sets the inside mechanism for 4.3 either automatic or manual closingof the circuit after the latter has been opened by the thermostatswitch. I may use a pair of signal lights to keep the operator informedwhether the manual or the automatic reset is on.

.11) It is thus seen that my new device is readily attached to any kindof electric implement for controlling its operation in various ways. Myinvention makes it unnecessary to incorporate thermostat switches inelectric heating appliances 5.; for temperature control, as heretoforedone, be;

cause one of my little control boxes takes care of all such appliancesin a household. The novel features and practical advantages of myinvention will be fully understood from a description of theaccompanying drawings, in which Fig. 1 shows one form of my controldevice in face View;

Fig. 2 is a side view of Fig. 1;

Fig. 3 shows the interior of the box on a larger scale, with thethermostat switch in normal circuit-closing position and the automaticreset on;

Fig. 4 represents a section on line 4-4 of Fig. 3;

Fig. 5 is similar to Fig. 3, except that the thermostat switch is openand the automatic reset is ofi, so that the switch remains open;

Fig. 6 shows a side view approximately on the broken line 6-6 of Fig. 5;

Fig. 7 is a transverse section on line 'l'! of Fig. 5;

Fig 8 is a fragmentary view on line '8 of Fig. 5;

Fig. 9 represents an enlarged section on line 9-9 of Fig. 5 to show moreclearly the construction of double rheostat used in this particularembodiment;

Fig. 10 illustrates in perspective a certain locking member adapted toprevent operation of the manual and automatic reset arrangement when Ithe thermostat switch is in the position shown in Fig. 5;

Fig. 11 is a view similar to Fig. 3, but showing the parts of thethermostat switch in an intermediate position just before they snap intothe final circuit-breaking position of Fig. 5;

Fig. 12 shows an enlarged fragmentary view 30 on line l2-i2 of Fig. 7 tobring out more clearly the switch connections that operate the twosignal lamps associated with the manual and automatic reset arrangement;

Fig. 13 is a section on line I3l3 of Fig. 12;

Fig. 1 1 is a circuit diagram of the electrical connections for thevarious parts of the control box shown in the preceding figures;

Fig. 15 shows a modified form of thermostatic control mechanismembodying my invention; Fig. 16 represents a side view on the brokenline lS--!6 of Fig. 15;

Fig. 17 is a plan view approximately on the broken line 11-11 of Fig.15;

Fig. 18 is a fragmentary face view showing the thermostat switch of Fig.15 in open position; and

Fig. 19 is a circuit diagram of the electrical connections in thecontrol box of Figs. 15-18.

Referring to Figs. 1 and 2, there is a box or casing I provided with acover plate I2 from which project three finger pieces I3, I4 and IS. Thefinger pieces I3 and I4 extend through slots I5 and 11, respectively,which may be formed in ornamental escutcheon plates I8 and I9. Onopposite sides of the slidable finger piece I3 are glass windows orlenses and 2|, which are preferably colored. In Fig. l, the lens 20 hasbeen assumed to be green and the lens 2! red, but these colors may bechanged as desired. The finger piece I5 is shown in the form of a rotaryknob having a pointer 22 arranged to move over an index 23. The cover I2of box I0 is preferably removable and is held in place by screws 23,which enter holes in bosses 24' at the edge of the box. To permitremoval of the cover, the finger pieces 13, I4 and I5 are detachablyconnected with their associated operating members inside the box, aswill later be explained. A cable 25 comprising a pair of electricconductors leads into box I9 at one end for connecting certain operativeparts in circuit. This cable is supposed to terminate in a plug adaptedto be inserted in an ordinary house-lighting circuit. It is immaterialwhether the current is direct or alternating At the other end of box IEIis a switch socket for receiving a plug 26 connected to a cable 21,which consists of-a pair of conductors leading to a suitable electricappliance, such as a heating device, an electric fan, a radio receiver,or any electric mechanism intended to be controlled by the apparatus inthe box.

. The various results obtained by a manipulation of the finger piecesI3, I4 and I5 are the following: When the finger piece I3 is at theright, as shown .in Fig. 1, a thermostatic switch in box I0automatically opens and closes the work circuit at predeterminedintervals. If the appliance attached to cable 21 is an electric heatingimplement (for example, a fiat iron, waflie iron, toaster, and thelike), the automatic opening and closing of the circuit keeps thetemperature of the implement within the desired limits. This temperaturemay be controlled by turning the knob I5 to set the pointer 22 at anymark on scale 23. When the pointer is in position 2212 opposite thelowest mark on the scale, the prevailing temperature of the heatingappliance connected to box I0 is at its lowest limit, while the 50highest temperature is obtained by moving the pointer 22 to theindicator mark I 0, as shown in full lines in Fig. 1. When the pointeris in the extreme position 22b, the circuit-controlling operation isentirely eliminated and the box operates like an ordinary switch. If thefinger piece I3 is shifted to the left end of slot I6, the thermostaticswitch inside the box opens the circuit after a predetermined interval,and the circuit remains open until manually closed by moving the switchpiece I4 to on position.

Signal lamps inside of box ID are automatically lighted to indicatewhether the automatic reset or the manual reset is on. Thus, when thefinger piece l3'is moved to the right, as shown in Fig. 1, the red lens2| is lighted and the operator knows that, as long as this red lightis'on, the temperature of the connected heating appliance is underautomatic control. When the operator shifts the finger piece I3 to theleft, the green lens 20 is lighted to inform him that the circuit willbe Open after a certain interval and will remain open until manuallyclosed by means of the finger piece l4. When the manual reset is on, theinterval of time during which the circuit remains open is regulated byturning the knob I 5 to move the parts of the control mechanism aredesigned.

These time intervals need be only approximate, for clock-like precisionis not necessary.

The base or bottom plate 28 of box ID has an upstanding lugor boss 29which carries a thermostat bar 30 of usual bimetallic construction. Thebar 30 is preferably U -shaped and one end of it is rigidly connected tolug 29 by bolts 3! or otherwise. The supporting lug 29 may be castintegral with plate 28, or it may be a separate piece attached to theplate in any practical Way. The thermostat bar 38 may be of any suitableshape, but I prefer a U-shaped bar, because the curved portion 30' actslike a hinge about which the main body portion of the bar moves duringpredetermined changes of temperature;

An insulated coil 32 is mounted on thermostat bar 30 for heating thesame to high temperature limits. This heating coil may consist of fineresistance wire wound on an insulating jacket or sleeve of asbestos,mica, or other suitable material; The circuit connections of coil 32will be described later on. It is enough to say at this time that, whenthe coil 32 is connected in circuit, the heating effect of the currentpassing:

through the high resistance wire raises the temperature of thermostatbar 30 so that the latter moves toward the left from its normalposition. This will be clear by comparing Figs. 3 and 5.

Let us now see what happens during this riibvement of the thermostat bar,at predetermined high temperature.

A switch lever 33 is pivoted at 34 on a bracket 35 projecting upwardfrom the bottom plate 28 of box I 0. ing bracket 35 may either beintegral with plate 28 or attached thereto as a separate part. One endof switch lever 33 has a lateral extension 33 adapted to receive a screwmember 31 which carries the finger piece I4. This finger piece may be adisk attached to (or forming an integral enlargement of) the screwmember 31, which is removably secured to the lateral extension 36 bysimply screwing it tight. Consequently, by

turning the finger piece I4 in a left-handed way,

the member 31 is unscrewed and can be removed. The other end or switchlever 33 carries a U- shaped spring blade 38, which is provided with aninsulated contact piece 39 of good conducting'metal. carries a head 40on which two insulated contacts M and 42 are mounted. If the head 43 isof metal, the contacts 4I-42 are mounted on an insulating plate 43attached to the head. as will/be clear from Fig. 11. The contacts M and42 are normally engaged by the bridge piece 39 to close the circuit ofthe'electric appliance connected to cable 21. The switch member 39 isheld in pressure engagement with contacts 4| and 42 by a contractingcoil spring 44, which is connected at one end to a cross-pin 45 on lever33 and at the other end to a fixed pin 43 mounted on the bottom plate 28of box It). In Figs. 3, 5 and 11, the spring 44 is diagrammaticallyindicated for clearness by a dotted line,

As in the case of lug 29, the support- The free end ofthermostat bar 33i which may be considered as representing the axis of pull or tension ofthe spring.

It is clear from Fig. 3 that, in the normal position of thermostat bar30 and switch arm 33, the tension line of spring 44 is to the right ofpivot point 34 of lever 33, so that the switch member 39 is held in firmpressure engagement with the insulated contacts 4| and 42 to close theelectric circuit through heating coil 32 and cable 21. When thetemperature of thermostat bar 30 reaches a certain point, the upper endof the bar begins to move toward the left, as

viewed in Fig. 3, and pushes the upper end of switch lever 33 in thesame direction. The switch plate 39 remains in engagement with contacts4| and 42 until the tension line of spring 44 crosses the pivot 34,whereupon the spring quickly snaps the lever 33 away from the thermostatbar 30 'against a fixed stop 47. .During this sudden movement of switchlever 33 under the action of spring 44, the switch member 39 is jerkedaway from contacts 4| and 42, so that the circuit is abruptly openedwithout arcing. Fig. 11 shows the movable members 30 and 33 just beforethe moment of snapping, while Fig. 5 shows the switch lever 33 in openposition. When the switch lever 33 is in normal circuit-closingposition, as shown in Fig. 3, the finger piece M on the top 01 box I isat the left of slot I! to indicate that the switch is closed. When,however, the switch lever 33 is in open position, as shown in Fig. 5,the finger piece I4 is at the right of slot H to inform the operatorthat the switch is off.

When the circuit of heating coil 32 is opened by the switch plate 38 onlever 33, as above described, the thermostat bar 3llbegins to cool andmoves back to normal position. It is evident that, if the switch lever33 is left in the position shown in Fig. 5, the circuit remains open,irrespective of the movements of thermostat bar 38 on cooling. However,if the thermostat bar 38 is to be used for controlling the temperatureof the heating appliance attached to cable 2?, it is not sufilcientmerely to break the circuit when a predetermined high temperature isreached, but it is also necessary to close the circuit automaticallywhen the thermostat bar begins to cool. This automatic closing of thecircuit is accomplished in the present instance by means of a yoke 48pivoted on a cross-pin 49 carried bf the head 40 of thermostat bar 30.The yoke 48 is a U-shaped member conveniently made from a single pieceof sheet metal, having a cross-piece 58 at one end and a pair ofextensions at the other end. A pin 52 connecting the extensions 5|passes through a cam slot 53 of an arm 54 pivoted on a rotary shaft 55,which is carried by a bracket 56 secured to the bottom plate 28 byscrews 51,

or otherwise. The bracket 56 may have a lateral brace 58 rigidlyconnected to the adjacent side of box I 0 by a screw 59. The rotaryshaft 55 is mounted at its lower end in a socket 60 in the bottom plate28, and the upper end of the shaft extends into an aligned opening 6| inbracket 56. There are, of course, other ways of supporting the shaft 55,but the mounting just described has the practical advantage ofpermitting easy assembly of the parts and the removal of cover l2. Thecam arm 54 has a hub or collar 62 through which the shaft 55 extends,and a pin 63 connects these parts so that they always operate in unison.

The rotary'shaft 55 carries a segmental gear or pinion 64 arranged inpermanent mesh with a rack bar 65 supported for transverse reciprocablemovement by rollers 65 which are mounted on pins or studs 61 projectingupwardly from the base plate 28. The rack bar 55 has a lateral extension68 to which the shank 89 of finger piece [3 is attached. The shank 69may simply be a 5 screwthreaded extension of finger piece I3, wherebythe latter is rigidly yet removably connected to the rack bar 65. Whenthe finger piece I3 is shifted to one side or the other of slot IS, therack bar 65 rotates the segmental gear 64 i0 and therefore shaft 55. Thecam slot 53 of arm 54 is so shaped that, when the rack bar 65 is inright-hand position as shown in Figs. 3 and 11 that is, when the fingerpiece I3 is in the position illustrated in Fig. .1); the pivoted yoke 48on therl5 mostat bar 38 embraces the upper end of switch lever 33.Consequently, as the cooling thermo stat bar 30 moves back to normalposition after the circuit has been opened, the cross-piece 50 of yoke48 engages the upper end of lever 33 and pulls it toward the right untilthe tensioned spring 44 snaps the lever back to normal circuitclosingposition, as shown in Fig. 3.

The length of restoring yoke 48 is so calculated that the switch piece39 is not snapped into engagement with contacts 4 l 'and 42 until thethermostat bar has practically reached normal position. When the circuitis again closed, the current in coil 32 heats the thermostat bar 30 andthe circuit-breaking operation previously de- 39 scribed is repeated. Itis clear from Fig. 11 that the yoke 48 does not interfere with themovement of switch lever 33 to open position under -the action of spring44. The shape of cam slot 53 is such as to permit movement of thermostatbar 39 without altering the position of yoke 48. In other words, thecross-pin 52 of yoke 48 rides idly in the cam; slot during thethermostatic movements of the bar. This will be readily seen bycomparing Figs. 3 and 11. The intervals during which the circuit is opendepends upon the thermostatic characteristics of bar 30 and on thetemperature of the bar when the circuit of heating coil 32 isinterrupted. It lies within the expected skill of the mechanic to use athermostat 5 bar or equivalent member capable of performing its intendedfunction.

When it is desired to let the circuit remain open after it has beenbroken by the thermostat bar 30, as shown in Fig. 5, it is onlynecessary to 33 shift the finger piece l3 to the left. This causes therack bar to actuate the segmental gear 64 counterclockwise, as viewed inFigs. 3 and 5. As a result of this operation, the cam arm 54 is rockeddownward and the cam slot 53 throws the 55 front end of yoke 48 upwardout of the path of switch lever 33. This is clearly illustrated in Fig.

5. With the yoke 48 thus moved into inoperative position, the coolingthermostat bar 30 returns to normal position without actuating theswitch (11) lever 33. The cam slot 53 is so shaped that the pin 52 ridesidly therein during the thermostatic movements of bar 30 to permit theyoke 48 to remain in its inoperative condition. The pivotal mounting ofyoke 48 on pin 49 is such that the J yoke is safely held by friction ineither of its two positions. In addition to this frictional retainingmeans, the cross-pin 52 cooperates with the edges of cam slot 53 toretain the yoke 48 in one position or'the other. This will be understoodby 70 looking at Figs. 5 and 11.

Two electric signal lamps T8 and H are mountcd in ordinary sockets 12attached to the bottom plate 28 of casing 10. The lamp 10 is arrangedbelow the green lens 20 and the lamp II is below "lamp Hwhich'illuminates the red lens 2|.

the red lens 2|. When the finger piece I3 is moved toward the left, thecircuit of lamp 18 is automatically closed through a pair of switchcontacts 13 and 16. When the finger piece I3 is moved toward the right,the circuit of lamp 11 is closed through a pair of switch contacts 15and 16. These two pairs of contacts are shown in the form of springblades mounted in an insulating support indicated as a whole by 11. Thestructural details of this support are. best shown in the enlarged viewsof Figs. 12 and 13, to which I shall now refer.

The switch support 11 comprises an insulating base 18 secured to thebottom plate 28 of the box by bolts or screws 19. If the box I0 is ofmetal, a sheet 89 of rubber or mica may be interposed to fortify theinsulation of base 18 from the metal box. The base -member 18 carries apair of L- shaped insulating pieces 8i and 82 secured by screws 83 and89. The spring blades 19 and 16 are provided with right-angledextensions 19' and 18', respectively, for receiving the screws 83 and89, which are thus in good metallic contact with the spring blades. Thescrews 83 and 86 may therefore be used as binding posts for attaching aconductor 85 to spring arm 16, and a conductor 86 to spring arm 16. Theother two pressly recited in the claims, for it is obvious thattheseswitches may be mounted and arranged in any practical way.

The rotary shaft 55 carries a cam disk 93 arranged between the switcharms 13 and 15, and in alignment therewith. These two switch arms areeach provided at the free end with an insulating projection or button 94adapted to be engaged by the cam disk 93. When the rack bar 65 is movedto the right, as shown in Fig. 11, the cam disk 93 engages the roundedbutton 98 and forces the spring arm 15 into pressure contact with theadjacent arm 16, thereby closing the circuit through The operator isthus visually informed by an unmistakable signal that the automaticreset of the control box is on, and that the circuit will beautomatically opened and closed. When the rack bar 65 is shifted towardthe left -by means of the finger piece I3, the cam disk 93 engages theinsulated button 99 of switch arm 13 and moves the latter into contactwith the associated arm 16. This closes the circuit through lamp 18,which illuminates the green lens and informs the operator that thecontrol box is now set for manual closing of the switch. The cam disk 93may be provided with a pair of recesses for receiving the roundedbuttons 96, whereby the spring arms 13 and 15 hold the cam disk and allconnected parts in actuated position. These connected parts include thecam arm 59, rack bar 65 and finger piece I3.

The finger piece I5 is connected to a rod 96 which operates a pair ofrheostat arms 91 and 98 arranged to move over separate resistanceelements 99 and I99, respectively. In the broader aspect of myinvention, the two rheostats con-' trolled by the rotary knob I5 may beof any practical construction, but in Fig. 9 I have shown a rheostatassembly that is easily put together. The various parts comprising thedouble rheostat are mounted on an insulating plate I81 secured to thebottom of the box by screws I92 or otherwise. The resistance elements 99and I 00 may simply consist of fine wire wound on arcuate insulatingstrips I03 and I96, respectively, which are firmly set in concentricgrooves I 95 and I06 in disk WI. The outer resistance element 99projects above the inner resistance element I09, so that the insulatedcontact arms 91 and 98 may engage these elements without interferingwith each other. This will be clear from Fig. 9. The shaft 96 extendsinto a metal sleeve I81 to which it is connected by a cross pin I98. Themetal sleeve I81 extends through a central opening in disk IM and isheld against axial displacement by a flange I99 bearing against a metalwasher IIII seated in the recess N2 of the disk. The metal sleeve I91carries an insulating bushing H9, which is locked to the sleeve by a keyIM or otherwise. The contact arm 98 is mounted on bushing I I 3 andisconnect ed thereto in any practical way, as by a key H5. The rotarycontact arm 98 is spaced from the insulating disk I III by a metalcollar or washer II6 mounted on bushing I I 3. The collar I I 6 bearsagainst a metal ring I I 1 inserted in the base plate I8 I. Aninsulating ring or collar I I8 holds the outer contact arm 91 properlyspaced from the inner arm 98. The metal sleeve I91 is formed with anaxial slot or groove H9 adapted to receive a lug or projection I20 onarm 91, whereby the latter is locked to the sleeve.

An expanding coil spring I2I surrounds the sleeve I81 between the hubportion 91' of arm 91 and a washer I22 adjacent the cross pin I08. Thespring I2I holds the rheostat arms 91 and 98 in firm pressure contactwith their respective resistance elements 99 and N16. The metal ring H1is part of a contact strip I23 (see Figs. 3 and 5) mounted on theinsulated base I9I and terminating in a binding post I2 3. The metalwasher III), which is always in electrical contact I with the metalsleeve I01, may be part of (or otherwise connected to) a conductingstrip I mounted on the underside of disk IOI and terminating in a secondbinding post I26. It is seen from this that. the insulated binding postsI24 and I26 are electrically connected to the rheostat arms 98 and 91,respectively. These two arms and their associated resistance elements 99and I08 are completely insulated from each other, so that we really havetwo rheostats in one. parts above described are very easily assembled onbase plate I0| for insertion into the casing III as a unitary device. Ifthe signal lamps 10 and 1| are omitted, the rheostat parts 98I00 are notnecessary.

The rotary movements of rheostat arms 91 and 98 are limited by a pair offixed stops I21 and I28 mounted on the insulating base IIII. rheostatarms are moved against the stop I21, as shown in Fig. 3, the arm 91 maybe out of contact with resistance element 99 and simply rest on theinsulated core I93. This cuts the resistance 99 out of circuit andmaximum current passes through the heating coil 32, because theresistance is in shunt to the coil. sistance wire 99 may, however, beengaged by the arm 91 when the latmr rests against stop I21 to includethe maximum amount of resistance in shunt to the heating coil 32. ,Ineither case, when therheostat arm 91 is moved against stop I21.

The end turns of re- When the y the current flowing through coil 32 isof maximum value. This will be made clear when I describe the circuitdiagram in Fig. 14. The other rheostat arm 98 is at the extreme end ofthe associated resistance element I when that arm is moved against thestop I21, so that practically all the resistance is cut into the circuitof lamp 10, which now burns very dimly.

The full-line position of rheostat arm 91 (and also arm 98) in Fig. 3corresponds to the dottedline position 22a of the pointer 22 in Fig. 1.When the pointer 22 is opposite the indicator mark I0, as shown in fulllines in Fig. 1, the rheostat arms 91 and 98 are in the positionillustrated in full lines in Fig. 5. This position of the rheostat arms,it will be observed, is 180 degrees from the position shown in Fig. 3,and the amount of resistance 99 now included is a minimum. The arms 91and 98 do not engage the stop I28, and they are therefore not in theirextreme left position. When the knob I5 is turned to move the pointer 22into position 22b opposite the indicator marked 23 (see Fig. 1), the arm91 engages the terminal 99' of resistance wire 99 and the latter isentirely out out. At the same time, the arm 98 includes a minimum amountof resistance I00 in the circuit of lamp 10, so that the same burns withmaximum brightness. Between the two extreme positions of the rheostatarms as defined by the stops I21 and I28, these arms may be moved to anyintermediate position to regulate the amount of current passing throughthe heating coil 32. As will appear later, by regulating the current incoil 32, it is possible to control the temperature of the electricheating appliance connected to the control box I0, or to regulate theinterval of time during which the circuit shall remain closed.

The base plate 28 of box I0 is provided with an insulating strip I29which carries a pair of binding posts I30 and I3I for connecting thewires of cable 25. This connection is permanent, for the cable 25 issupposed to be a part of the control box as sold in the market. It isonly necessary for the user to insert the plug I32 of the cable into thehouse-lighting circuit (see Fig. 14). The outer casing or box I0contains a suitable switch I33, which may conveniently be secured to theend wall I34 of the box by a strip I35. An opening I38 in the end wallI34 permits the insertion of plug 26, which is supposed to be connectedto whatever electric appliance is intended to be controlled by thethermostatic switch mechanism in box I0. The structural details ofswitch I33 are immaterial and need not be shown or described, becausevarious styles of switches may be purchased in the open market. It isenough to say that the contacts inside the switch are connected to apair of outside binding posts I31 and I38.

I have already described how'the pivoted yoke 48 mounted onthethermostat bar 30 is moved into operative and inoperative positions bysimply shifting the finger piece I3 which actuates the rack bar 65. Itis clear from Fig. 5 that, when the switch lever 33 is open, the yoke 48can not be rocked down to operative position, because the cross-piece 50would strike the top of the switch lever. means for automaticallylocking the rack bar 85 against operation-when the switch lever 33is inopen positon. A bracket I39 fixed on the base plate 28 of casing I0carries a pin I40 on which 3, depending arm MI is pivoted. As best shownin Fig. 10, the arm I4I has a right-angled extenconnected to conductorI52.

I have therefore provided sion I42, which terminates in a lateral catchI43. The lower end of arm MI is in the shape of a yoke I44 adapted tostraddle the pivoted switch lever 33. Theslidable rack bar 65 has a pairof notches I45 and I46. Referring to Fig. 5, it is 5 seen that when theswitch lever 33 is in open position, the free end of arm I42 is rockeddown, so that the catch I43 engages notch I45 of rack bar 65, wherebythe latter is positively locked against movement toward the right. Therack bar can not be moved toward the left, because it is already in itsextreme left position, abutting against the left side of casing I0. Whenthe rack bar 65 is in the position shown in Fig. 11, the catch I43engages notch I46 as long as the switch lever 33 is in open position.This may be explained somewhat more simply by referring to v Fig. 1:When the finger piece I4 is in ofi position at the right end of slot I1,the finger piece I3 is locked against movement, no matter at which endof slot I6 it happens to be.

Fig. 14 indicates diagrammatically how the various electrical parts incontrol box I0 are operatively connected in circuit. In describing theseconnections, I shall use the convenient word wire to indicate anysuitable electrical conductor, whether in the form of a wire, bar,plate, rod, or what not. A wire I41 connects terminal I3I with contact4|, and contact 42 is' connected by wire I48 to the rheostat terminal99'. One side of heating coil 32 is connected by Wire I49 to wire I48 atpoint I50, and the other side of the coil is connected by wire I5I tobinding post I38 of switch I33. The other binding post I31 of thisswitch is connected to terminal I30 by wire I52. One end of resistanceelement I00 is connected to a binding post I53 on disk MI, and a wireI54 connects this binding post to conductor I52. The signal lamp 10 isconnected in series with conductors 9| and 92 already referred to. Theother signal lamp 1| is connected in series with conductors 86 and I55,the latter being A wire I56 connects the two conductors 92 and I48, anda resistance I51 may be included to cut-down the normal voltage in lamps10 and 1| if necessary. The diagrammatic outline I58 is intended torepresent any suitable current-consuming device connected to the cableleads 21. If this device is a heating appliance, the outline I58 may beregarded as indicating an electric heating unit. The position of therheostat arms 91 and 98 in Fig. 14 corresponds to the full-line positionof pointer 22 in Fig. 1 opposite the indicator mark I0. The position ofcam disk 93 in Fig. llcorresponds to the position of finger piece I3, asshown in Fig. 1; that is to say, the automatic reset is on.

Assuming the switch arm 33in normal circuit-closing position, thefollowing circuit connections are established in Fig. 14: from bindingpost I3I, wire I41, contacts 4| and 42 which are now closed by contactpiece 39, wire I48 to point I50, where the current divides into threepaths, one of which goes through wire I49, coil 32, wire I5I, switch I33which connects the electric device I58 in circuit, and through wire I52to return terminal I30. It is thus clear that the heating coil 32 is inseries with the current-consuming element I58. The second current pathfrom point I50 goes through wire I48 to binding post 99', through theresistance element 99, arm 91, wire I25, binding post I26, wires I59 andI5I, and from there through the electric appliance I58, as previouslydescribed. The resistance 99 (6 is therefore in shunt to the heatingcoil 32, and the amount of resistance cut in determines the value of thecurrent passing through the coil. The third current path leading frompoint I58 goes through lamp resistance I51, wire I95 to point I60, wire92, across the closed switch contacts I5 and I6 through the signal lampII, and through wire I55 to the return lead I 52. The si nal lamp IIilluminates the red lens 2|, whereby the operator is visually informedthat the automatic reset is on. No current passes through the lamp III,because the switch arms I3 and 14 are open.

The circuits described in the preceding paragraph remain closed as longas the connecting piece 39 of switch lever 33 engages the contacts IIand 92 of thermostat bar 30. The current passing through coil 32 heatsthe thermostat bar so that the latter moves toward the left and finallycauses the spring 98 to snap the switch lever 33 into open position, asheretofore explained in detail. When the contacts III and 82 are broken,the circuits of coil 32, lam YII and consuming device I58 are opened. Aswe are now assuming that the yoke 98 is in operative position, thesecircuits will be automatically closed when the thermostat bar 30 hassuificiently cooled to pull the switch lever 33 back to normal position.The circuits remain closed until the current in coil 32 has raised thetemperature of thermostat bar 39 to a predetermined amount. In this way,the current-consuming device I58 is automatically cut into and out ofcircuit at predetermined intervals.

It is evident that the prevailing temperature of the heating applianceI58 depends upon the frequency'at which the circuit is opened, and thisfrequency of interruption is governed by the amount of current passingthrough coil 32. As already explained, the current through coil 32 iscontrolled by the rheostat arm 91, which is manually set by the fingerpiece I5. Since the resistance 99 is in shunt to coil 32, it is clearthat the current through the coil is increased proportionately to theincrease of resistance 99 in circuit. With the arm 91 in the positionshown in Fig. 14, a minimum amount of resistance 99 is in shunt to coil32, so that minimum current flows through the coil, and it takes acorrespondingly long interval of time to heat the thermostat bar 30 tocircuit-opening temperature. Since the circuit thus remains closedthrough the longest periods of time, the prevailing temperature of theheating appliances I58 is correspondingly high. As the pointer 22 isturned clockwise over the indicator 23, more resistance 99 is graduallyincluded and the current through coil 32 is correspondingly increaseduntil the maximum amount of current flows through the coil when thepointer 22 is in position 22a. With a maximum flow of current throughcoil 32, it takes a minimum amount of time to heat the thermostat bar 30to circuit-opening temperature. Since the circuitthrough the heatingappliance I58 is now interrupted at highest frequency, it is manifestthat the prevailing temperature of the appliance is at its lowest.

Between the extreme positions I and ID of pointer 22 for lowest andhighest temperature limits in device I58, it is possible to obtain anydegree of intermediate heat by simply turning the pointer to therequired mark. When the pointer 22 is at the extreme left position 22b,

- the rheostat arm 97 engages the terminal 99 and the heating coil 32 isshort-circuited, so that practically no current passes therethrough.This means that the thermostatic control is eliminated, and the switchcontacts II-92 remain closed for a continuous flow of current throughthe consuming device I58. the legend Time control out is associated withthe indicator mark 23. In other words, when the pointer 22 is inposition 22b, the control box acts like an ordinary switch.

The resistance element I09 is connected in se- 10 ries with the signallamp III for varying the brilliancy of the light in accordance with theposition of rheostat arm 98. When the switch arms 13 and I4 are open,the resistance I88 is inoperative and the arm 98 moves idly along withthe 15 other rheostat arm 91. As previously explained, the lamp I0 is incircuit only when the finger piece I3 is moved to the left toward thegreen lens 20. Assuming the switch IS-I I closed by the cam disk 93, andalso assuming that the contacts 20 M and 42 are closed, the circuit oflamp I9 is completed through rheostat arm 98 and resistance I00. Whenthe arm 98 is in the position shown in Fig. 14, nearly all theresistance is cut out and the lamp I0 burns with high luminosity, 25which is increased to a maximum when the pointer 22 is in position 22b.When the rheostat arm 98 is in extreme right position against the stopI27, nearly all the resistance I00 is in series with lamp ID, so that itburns with low visibility. For

any intermediate position of arm 98, the luminosity of lamp ID variesproportionately.

The brightness of lamp I9 is a rough visual indication of the prevailingheat in appliance I58, or of the period during which the circuit remains855 closed. Thus, when the green lens 29 glows brightest (the greenbeing suggestive of coolness),

' the operator is informed that the heating appliance I58 is operatingat lowest temperature, and

vice versa. If the device I58 is not a heating 40 instrument but someother kind of current-consuming device, such as an electric fan, washingmachine, radio receiver and the like, the highest glow of green lens 20tells the operator that the circuit will remain closed for the shortestspace 45 of time. It is, of course, possible to connect the resistanceI00 in such a way that the lamp III shines brightest when the operatingcircuit remains closed the longest period of time, which happens whenthe current through the thermostat 50 coil 32 is weakest. If the varyingbrightness of lamp I0 is not desired, the rheostat 98-I00 is omitted andthe wire is connected directly to wire I54. In the broader aspect of myinvention, the signal lamps I9 and II are not necessary, but 55 theyserve the purpose of indicating visually the opening and closing of thecircuit and thereby add to the practical value of the invention.

Figs. 15-19 illustrate a modified construction which accomplishes thesame results as the em- 60 bodiment of Figs. 1-14, but with the addedadvantages of greater simplicity. To avoid needless repetition, thoseparts in Figs. 15-19 that correspond to-similar parts in Figs. 1-14 areindicated by the same reference numerals without 55 further explanation.Referring to Figs. 15-19, a switch lever ISO is pivoted at IBI on a studI62 projecting from the bottom plate 28 of the control box. The lowerend'of switch lever I60 has a lateral extension I62 for receiving ashank I63, 70 which is supposed to carry a suitable finger pieceprojecting through a slot in the cover plate l2 of the box. It may beassumed that switch lever I60 is manually operated in the same way asswitch lever 33. Afblock or bracket I68 mounted on the 75 This explainswhy in Fig. 1 5

bottom plate 28 carries a spring arm I65 which terminates in a V-shapedend I66 arranged to engage a pin I61 projecting laterally. from switchlever I69. The V-shaped end of spring I65 firmly holds the pivoted leverI69 in either of its two positions. The switch lever I69 carries twoinsulated contacts I68 and I69. Th'e fixed block or bracket I64 isprovided with an insulating plate I19 on which three contacts I1I, I12and I13 are mounted. When the switch lever I69 is in normalcircuit-closing position, contact I68 engages the fixed contact HI andswitch member I69 spans the two contacts I12 and I13. The movable switchparts I68 and IE9 are preferably spring members of sufiicient resiliencyto insure a firm pressure engagement with the associated contacts I 1 I,I12 and I13, so that the circuits are held positively closed.

An arm I14 ispivoted at I15 adjacent the thermostat bar 39, and the freeend of this arm carries an extension I16 which-may be shaped from asingle piece of stiff sheet metal. The extension I16 comprises a pairofxspaced fingers I11 and a tail I18 bent downwardly at I19. Acontracting coil spring I99 is connected at one end to a pin I 8|projecting laterally from arm I14, and at'its lower end to a fixed studI82 on the bottom plate 28. The pivoted arm I14 is arranged in the pathof thermostat bar 39 and is thus controlled by the position of the bar.A U-shaped frame I83 is slidably mounted on a pair of studs I94 securedto bosses I85 on the bottom plate 28 of the control box. The sides I86of frame I83 are provided with aligned slots I81 through which the studsor pins I84 extend. These supporting studs may be pins screwed intobosses I85 and may have bearing sleeves I88 to facilitate the movementsof frame I83. The sides I86 of this frame are provided with shouldersI89 and I99. One end of the slidable frame I83 is bent laterally toprovide a cross connection I9I which carries an insulated contact plateI92. A stud or bracket I93 on the bottom plate 28 carries a springmember I94 on which two insulated contacts I95 and I96 are mounted. Aspring arm I91 supported at one end on the bottom plate 28 carries atits free end a roller I98 arranged to engage a cam projection I99 on theslidable frame I83. The spring-pressed roller I98 cooperates with thecam projection I99 to hold the slidable frame I83 in either of its twopositions.

The contracting coil spring I89 connected to the pivoted arm I14normally holds the fingers I11 against the shoulders I89 of frame I83,so that the switch plate I92 is pressed firmly against the resilientlymounted contacts I95 and I96. The cam roller I99 assists the spring I89in normally holding the frame I83 in circuit-closing position. As thetemperature of thermostat bar 39 increases, due to the current inheating coil 32, the free end of the bar moves toward the left andengages the arm I14, so that the latter is gradually pushed toward theleft out of contact with frame 83, which remains stationary for the timebeing. When the fingers I11 move away from the shoulders I89 of frameI83, the latter is firmly held in circuit-closing position by thespring-pressed cam roller I98, so that the circuit remains closed whilethe thermostat bar 39 and arm I14 are moving toward the left. When thetension line-of spring I89 crosses the pivot point switch contacts I95and I96 are thus opened so quickly that'no arcing occurs. The thermostatbar 39 being disconnected from arm I14 does not partake of the snap-overmovement of the arm by spring I89, so that the thermostat bar does notback toward the right to normal position. The

initial return movements of bar 39 do not affect the actuated arm I14,because the free end of the bar is out of contact with tail I18 of thearm. However, when the free end of the cooling thermostat bar 39 engagesthe extension I19 of arm I14, as indicated in Fig. 18, the thermostatbar and the arm are coupled together so that further movement of the bartoward the right carries the arm along. When the tension line of springI89 moves to the right of pivot I15, the arm I14 20 is quickly snappedback to normal position with such force that the slidable frame I83 isabruptly shifted to the circuit-closing position shown in Fig. 15. Thecircuits being thus closed again, the

heating action of coil 32 causes the thermostat bar 39 to open theswitch contacts I95-I96 after a predetermined interval, and then thecircuit is again automatically closed in the manner described. When thefingers I11 of arm I14 move away from the shoulders I99 of frame I93,the

latter is firmly held in actuated position by the spring-pressed camroller I98. It is, of course, understood that the snap-over spring I89is sufficiently strong to operate the frame I93 against the retardingfriction exerted by the relatively weak spring I91. t is to be notedthat the preliminary movement of the thermostat bar 39 and pivoted armI14 have no effect on the position of the slidable switch frame I83, sothat the circuit remains positively closed and open until 40 the momentwhen the arm I 14 is actually snapped into final position by thetensioned spring I89.

The slidable switch frame I83 is utilized to throw the pivoted switchlever I69 into circuitopening position by means of a manually adjustableconnection, which I shall now describe. An arm 299 is pivoted at one endon a pin or stud 26I projecting upwardly from the bottom plate 28. Asuitable finger piece 292 is connected to arm 299 and projects through aslot 293 in the top plate or cover I2 of the box. A right-angled frame294 is connected to arm 299 by a pin 295. Two pairs of spaced rollers296 guide the frame 294 in its movements. The upper end of frame 294hasa lateral extension 291 which n terminates in a head 298 arranged toproject between the spring arms 13 and 15. These are the same as (orcorrespond to) the spring arms similarly numbered in the construction ofFigs. l-14.

If the reoiprocable frame 294 is of metal, the

switch-operating head 298 should be of insulating material. The lowerend of frame 294 carries a pin 299 on which a tongue 2I9 is pivoted. Apost 2 on bottom plate 28 carries a spring blade 2I2 which is secured atthe middle'and shaped at the ends to receive the free end of arm 299 ineither of its two positions. Any other means may be provided forreleasably holding the pivoted arm 299 in the position to which it hasbeen moved by the finger piece 292.

When the arm 299 is in the position shown in Fig. 15, the tongue 2I9 onframe 294 is out of the path of frame I83, so that the projecting edgeI83 of this frame does not engage the switch lever I69, which thereforeremains in circuitclosing position, as will be clear from Fig. 18.Consequently, when the frame I83 is' moved back to normal position bythe cooling of thermostat bar 30, the circuit is automatically closedthrough heating coil 32 and working device I58. If the user does notdesire this automatic reset, but wants the circuit to remain open untilmanually closed, he simply pushes the finger piece 202 down so that thetongue 2I0 now hangs in the space between the upper end of lever I6!)and the edge I83 of frame I83. This coupling position of tongue 2 I3 isindicated by the dotted outline 2I3- in Figs. 15 and 18. Therefore, whenthe frame 583 is next actuated to the left by the pivoted arm I14, theswitch lever I60 is rocked counterclockwise until it strikes the fixedstop 2 I3 against which it is held by the spring I65. The

opening of switch contacts I12 and I13 prevents.

closing of the circuit through coil 32 and device I58, even after theframe I83 has been moved back to normal position. This will be clearlyunderstood from the circuit diagram of Fig. 19, to which I shall nowrefer.

Switch contact I95 is connected to terminal III! by wire 2H5, andcontact I95 is connected to one side of coil 32 by wire 2I5. Theterminal 99' of resistance element 93 is connected by wire 2I6 to wireM5 at point 2I1. A wire ,2I8 connects the switch contact I13 with theother side of coil 32, and wire 2I9 connects the rheostat binding postI26 to wire 2I8. The rheostat 9199 is therefore in shunt to thethermostat coil 32, the same as in the embodiment of Figs. 1-14. Switchcontact I12 is connected to one side of switch I33 by wire 22D, and wire22I connects terminal I30 to switch contact IN. The insulated contactI68 mounted on the pivoted switch lever ISO is connected by wire 222 toone side of the signal lamps and TI through parallel branch wires 223and 223, respectively. The other side of lamp 10 is connected by wire225 to switch contact 13, and the other side of lamp H is connectedbywire 226 to the movable switch member 15. The switch contacts 13 and 15are connected in parallel to conductor 2H3 by wires 221 and 228. A wire229 is connected at 233 to conductor 22I, and the other end of the wiregoes to switch I33. A resistance 23I may be inserted in conductor 22I toout down the voltage passing through lamps 10 and 1 I. if that should befound necessary.

It is clear from Fig. 19 that the circuit of heating coil '32 andworking device I58 is closed through the switches I95I95 and I12I 13 inseries, so that both of these switches must be closed to complete thecircuit. As long as the switch contacts I12-I13 remain closed, thethermostat bar 39 automatically closes and opens the circuit throughcoil 32 and device I58 at predetermined intervals. The frequency of thiscurrent interruption is controlled by the rheostat arm 91, as previouslyexplained in detail. When the controlling arm B is pulled down to movethe tongue 2I0 into coupling position, the opening of switch contactsI95--I96 is accompanied by the opening of contacts I68 I1I and I12-I13.Since the switch lever I60 is held in open position and has noconnection with thermostat bar 30, the circuit through coil 32 anddevice I58 remains open even after the slidable frame I83 has been movedback to "normal position by the springactuated arm I15. The circuittherefore remains open until the lever ISO is manually restored tonormal circuit-closing position by means of a suitable piece on thecover of the box, as

more fully explained in connection with lever 33 in Figs. 1-14.

The circuit of signal lamps 10 and H is closed through contactsl58-'I1I, but only one lamp is lighted at a time, because the head 208of the 5 movable frame 205 closes either the switch contacts 13-14 oflamp 10 or switch contacts 15-16 of lamp 1|. When the lever 200 is inthe position shown in Fig. 15, the automatic reset is on and the circuitis closed through lamp H which 10 lights the red lens 2L When the arm200 is pulled down for the manual reset, the switch contacts 13-13 areclosed and lamp 111 shines through the green lens 28. In this case thereis no rheostat for lamp 10 to vary its degree of brightness, but 15 sucha rheostat may be incorporated if desired.

It is to be noted that no special provisions are necessary to lock thearm 200 against operation when the frame I83 is moved to the left,because the frame automatically acts as a stop for tongue 20 2 I 0, sothat the finger piece 201 can not be pushed down by the operator.

The box or casing I3, which need be no bigger in actual size than theillustration of Fig. 1, can be made of molded insulating material of the2 bak-elite type, or cast of light strong metal like aluminum, orstamped from sheet metal. The base plate 28 is here shown as a separatemember attached to the body of the box by screws 28, but it mayobviously be an integral part of the body. If desired or foundcommercially advisable, the inside of the box may be lined with asbestosor other heat-insulating material. The face view of Fig. 1 may also beconsidered as representing the box of Figs. 15-46, except that thetransversely slidable finger piece I3 is replaced by the finger piece202 movable lengthwise of the box. In its finished commercial form, thisbox is suitably colored and ornamented, particularly the cover I2 withits various legends and designs. To the housewife the most important useof my new control box is probably the regulation of temperature inelectric heating appliances, especially flat irons, which the automaticreset prevents from getting too hot or too cold By shifting the fingerpiece I3 or 202 to the manual reset, my controlling device becomes atime switch for automatically opening an electric circuit after apredetermined interval of time, which is variable by means of knob I5.Thus, by connecting a radio receiver or an electric fan to box ID, aperson in bed may fall asleep to the sound of music or a cooling breeze,and so many minutes later the radio or the fan, or whatever instrumentit may be, is automatically turned off. When the manual reset is on andthe pointer 22 is in position 22b, the box operates like an ordinaryswitch that holds the circuit closed until the finger piece I 3 is movedto off position. It is thus seen that one little box is capable ofcontrolling an electric circuit in a variety of ways without changingany outside connections, but simply by the easy manipulation ofconvenient finger pieces.

Although I have shown and described certain specific constructions, Iwant it understood that my invention is not limited to the details setforth. The various features of novelty included in my invention may bemechanically embodied in other ways than herein described, withouttieparting from the scope of theappended claims. It goes without sayingthat certain features of my invention may be used without others.

I claim as my invention: 1. The combination of a switch member, a 7

lit?

aoaaiae thermostat bar, an adjustable mechanical transmission connectionbetween said parts, said connection including means whereby saidthermostat actuates said switch member to open and closed positions inautomatically repeated sequence at predetermined changes of temperature,and manually controlled means for breaking said connection.

2. The combination of a movable switch ele ment, a thermostat element, amechanical connection between said elements whereby the thermostatelement at predetermined temperature changes opens and closes the switchelement in automatically repeated sequence, and manually controlledmeans whereby said connection is readily separable and restorable.

3. The combination of a movable element capable of occupying twopositions, a thermostat element, means whereby the movements of saidthermostat element at predetermined temperature changes actuate saidfirst element from one position to the other in automatically repeatedsequence, an adjustable finger piece, and means operated by said fingerpiece for mechanically connecting and disconnecting'said elements.

4. The combination of a thermostat member, an electric heating elementior said member, switch'mechanism operated by said member to open andclose the circuit of said element in automatically repeated sequence atpredetermined high and low temperature limits, a manually adiustableconnection adapted to prevent said thermostat member on cooling fromclosing said switch mechanism, and means whereby said adjustableconnection does not interfere with the thermostatic movements of saidmember.

5. The combination of a movable switch member adapted to occupy twopositions and to remain stable in either position, thermostatic con-=nections for automatically moving said member back and forth atpredetermined intervals, and manually controlled mechanical means forrendaring said connections inoperative in relation to said switchmember, said means permitting iree thermostatic movements of saidconnections while the latter remain out of engagement with said switchmember.

ii. The combination of an electric switch member normally incircuit-closing position, a heating coil controlled by said switchmember, a thermostat bar subject to the heat of said coil for actuatingsaid member to open the circuit, means whereby said thermostat bar oncooling automatically returns said member to normal circuitclosingposition, whereupon said coil again heats the thermostat bar until saidswitch is again opened, so that the circuit opening and closingoperations of said switch member by the thermostat bar are repeated inautomatic sequence,

and manually controlled mechanical connections ior rendering said meansinoperative without inmeans for eliminating the circuit-closingoperation of'said thermostatic means without interiering with themovements of said thermostatic means under changes of temperature, sothat said switch member remains in open position, said eliminating meansincluding a separable mechan-: ical connection between said thermostaticmeans and said switch member.

9. An electric switch comprising a pivoted contact lever mounted toassume two positions and 10 to remain stable in either position,thermostatic means mechanically connected to said lever forautomatically actuating said lever back and forth from one position tothe other at predetermined intervals, and manually controlled means forill breaking said mechanical connection and thereby eliminating oneoperation of said thermostatic means, whereby said lever remains inactuated position.

10. The combination of a movable switch member, thermostatic meansmechanically connected with said member for actuating the same to openand close an electric circuit in automatically repeated sequence atcertain intervals, manually controlled means for eliminating thecircuit-closing operation of said thermostatic means, whereby saidswitch member remains in open position, and a finger piece for movingsaid member to circuit-closing position.

11. The combination of a movable switch mem- $0 leer-adapted to occupytwo positions and to remain stable in either position, thermostaticconnections for automatically moving said member back and forth inrepeated sequence at predetermined intervals, said connections includinga transmission element movable back and forth by the thermostatic actionof said connections, and means whereby said element is manuallyadjustable to remain out of mechanical engagement with said switchmember durim the thermostatic 40 operation of said connections, andvisual signal means automatically controlled by said manual means forindicating the condition of said connections.

12. A normally closed switch member, thermo static means mechanicallyconnected with said member for automatically opening and closing saidmember'in repeated sequence at predetermined intervals, manuallycontrolled electric means ior varying said intervals, separate means foreliminating the circuit-closing operation of said thermostatic means bybreaking said mechanical connection, so that said switch member remainsin open, position, and a finger piece for moving said member tocircuit-closing position.

13. A thermostatic switch comprising a movable switch member normallyheld in closing position, a pivoted arm movable independently or saidswitch member, a spring connected to said arm for snapping the same inopposite directions against said switch member, whereby said armabruptly moves said switch member from one position to the other, andthermostatic means for rocking said arm about its pivot in alternatelyopposite directions to cause the snap-over move- 66 ments of the arm bysaid spring.

14. A thermostat switch comprising a pivoted snap-over member, athermostat bar mechanically connected with said member for moving saidmember from one position to the other, means 70 whereby the movements ofsaid thermostat bar in opposite directions at predetermined changes oftemperature cause said mechanical connection to operate said switchmember back and forth in automatically repeated sequence, a movable i5switch element operated by said member for opening and closing acircuit, said switch element being adapted to remain in either of itsactuated positions, and means whereby the preliminary movements of saidmember prior to the snapover operation do not afiect the position ofsaid switch element, which remains positively closed and open untilabruptly actuated by the snapover operations of said member.

15. A circuit control unit comprising an outer case or box, a movableswitch member in said case, a movable finger piece projecting from saidcase for operating said switch member, thermostatic means in said casefor operating said switch member, a second movable finger piece on saidcase, connections controlled by the second finger piece for causing saidthermostatic means to automatically open and close said switch member atpredetermined intervals, and means for causclosing said switch memberindependently of said thermostat element, and means controlled by thecircuit-opening position of said switch member for locking said deviceagainst operation until said switch member is manually restored toclosed position. 17. A circuit control unit comprising an outer box, amovable switch member in said box, a movable finger piece on said boxfor operating said switch member to close and open acircuit,thermostatic means in said box for operating said switch member, asecond movable finger piece on said box, connections controlled by thesecond finger piece for either causing said thermostatic means toactuate said switch member to open and closed positions at predeterminedintervals in repeated sequence or causing said switch member to remainin open position, a pair of difierently colored signal lamps carried bysaid box, and switches controlled by the position of the second fingerpiece for lighting either signal to indicate the operative relation ofsaid thermostatic means to said switch member.

18. A circuit control unit comprising an outer case or box, a movableswitch member in said case, a movable finger piece on said case foroperating said switch member to close and open a circuit, thermostaticmeans in said case for operating'said switch member, a second movablefinger piece on said case, connections controlled by the second fingerpiece for either causing said thermostatic means to automatically openand close the circuit at predetermined intervals or causing said switchmember to remain in open regulating the frequency of operation of said'thermostatic means.

19. A thermostat switch including a pair of stationary contacts, atemperature-responsive element, a rockable actuator operated by saidelement, a movable member carrying contact aoeaise means arranged toengage said stationary con"- tacts to close an electric circuit, aspring connected to said actuator, and means whereby said M spring urgessaid member toward said contacts in circuit-closing position of theactuator and 5 .away from said contacts in open-circuit position of theactuator, said spring being controlled by the movements of said actuatorto snap said member into circuit-breaking and circuit-closing positions.

20. In a circuit-controlling device, the combination of a switch, athermal element for operating the switch frornpne position to anotherwhen the thermal element becomes heated and for returning the switch tothe first position with a time-delay dependent upon the cooling of thethermal element, heating means for the thermal element controlled by theswitch, and means moperating the switch to and maintaining the same inopen position even when said thermal element remains heated.

21. In a circuit-controlling device, the combination of a switch, athermal element for operating the switch from a predetermined positionto another position when the thermal element is subjected to a certaintemperature and for re turning the switch to said predetermined positionwith a time-delay dependent upon a predetermined change of temperatureof the thermal element, heating means for the thermal element controlledby the switch, and means for operating the switch to'and maintaining thesame in open position even when said thermal element remains heated,said means including a handoperable pivoted member. i

22. In an automatic switch, the combination comprising, a thermostaticmember having an engaging portion, a movable switch actuator, apivotally mounted trigger biased in one direction and having extendingarms, one of said arms 40 adapted to directly engage said portion, andthe other of said arms directly engaging the actuator,

a movable switch arm operated by said actuator to open position, andmanually controlled means for preventing operation of said switch arm bysaid actuator, whereby the operation of said switch arm is taken out ofthe control of said thermostatic member.

23.,In a time-controlled circuit controller, a timed moving element, apair of relatively movable contacts, a movable member, and meansoperatively associating the moving element and the movable member tomove said contacts relatively to each other, said means including tworelatively movable parts which constitute a lost-motion drivingconnection and which engage only after one of said parts has rotatedthrough a certain angle, whereby there is eflected'a predeterminedmovement of the element without actuating the member.

24. In a time-controlled circuit controller, a timed moving element, apair of relatively mov-= able contacts, a pivoted arm, and meansoperatively associating the moving element and the pivoted arm to movesaid contacts relatively to each other, said means including two'relatively movable parts which constitute a lost-motion drivingconnection and which engage only after one of said parts has rotatedthrough a certain 7 angle, whereby there is efiected a predeterminedmovement of the element without actuating said arm.

' ADOLPH A. THOMAS.

